In fields such as clinical medicine, forensic sciences, environmental quality testing, food quality assurance, drug testing, and other areas, it has become possible to determine the presence and/or amount of trace substances in test samples even when such substances are present in very low concentrations (on the order of parts per million, or even per billion). For example, during testing of urine, it is now possible to detect and quantify trace quantities of most known illicit drugs. Further, as a result of such drug testing, positive test results may have a profound impact on the donor's career or employment. In the proper circumstances, positive test results may also result in criminal liability for the donor.
Such circumstances dictate that the security or chain-of-custody of the specimen be preserved and that any tampering of the specimen be immediately apparent. It is desirable that test results be verifiable by repeating the tests on an identical specimen. It is also important that the specimen be capable of being "split", in order that a secure portion of the specimen can be sent to another laboratory for independent confirmation of the test results.
Similarly, other liquid sampling procedures present the same issues of repeatability and integrity verifiability. For example, the U.S. Environmental Protection Agency conducts a variety of ongoing testing programs. These testing programs are intended to guarantee compliance with standards for maximum levels of toxic and/or radioactively contaminated liquids, such as plant effluent. In the event of a test indicating non-compliance with such a standard, it is important that the EPA be able to repeat the test on another, identical specimen. It is equally important that the EPA be able to verify that the specimen that is tested is indeed the specimen that was taken and that no foreign substances have been introduced into the specimen without being tamper evident.
Thus, there remains a need for a liquid specimen vessel that provides for more than one isolated specimen of a sample. Such a vessel should provide for splitting of the specimen for independent testing. The vessel should also minimize or even eliminate the possibility of contamination of the test specimen. Further, the vessel should automatically retain an archival specimen so that any tests may be repeated on an identical test specimen and the results of the tests verified. Such a specimen vessel should be easy to use and simple in construction. It should also present a geometric aspect that is sufficiently simple to be easily moldable by known molding techniques.